Method for identifying keys for controlling locks

ABSTRACT

A system for controlling access to a secure area includes a lock and an electronic access device for controlling access to a secure area. The lock includes pins for locking and unlocking the lock. The access device communicates with the pins for electrically measuring movement of the pins. The access device stores an unlock pin code for the predetermined position of the pins for unlocking the lock. The electronic access device electrically measures pin movement by a key and determines a key code for the key from the pin movement. A control device electrically communicates with the electronic access device for identifying the key code and determining when the key code matches the unlock pin code.

FIELD OF THE INVENTION

The present invention relates to access control systems, and moreparticularly, relates to access control systems having both mechanicalsecurity and electronic access control.

BACKGROUND OF THE INVENTION

Current access control systems may electronically monitor and controlaccess at an entryway to a secure area using, for example, a reader forreading an access card. Additionally, however, the secure areacontrolled by the access control system may include one or moreentryways having a mechanical lock. For example, doors may have bothmechanical security, e.g., a lock, and electronic access control, inthis case, the mechanical lock mechanism takes precedence over theaccess control logic. Additionally, the doors having a lock may beopened by unlocking the lock using a typical door key, or alternativelya master key which overrides the access control system. Alternativeaccess control systems and security systems may include electronicallyactivated mechanical locks. Such control systems may also includemultiple entryways, for example, on a floor of a building or the entirebuilding, for example, as shown in commonly-owned, and co-pending U.S.patent application Ser. No. (11/782,557), the entire contents anddisclosure of which is expressly incorporated by reference herein in itsentirety.

A shortcoming of such systems is that the access control system is notable to monitor when the door is opened by a key. Further, the accesscontrol system is not able to identify who is passing through thedoorway. If the system has a door position switch, the access controlsystem will have only a record of the door opening, but not an identityand record of the key which opened the lock mechanically. In an accesscontrol system which has a door position switch, the door opening eventwill appear as a forced entry. Another shortcoming of such systems isthat a person who is authorized to enter and uses the key entry, eithera typical key or a master key, will trigger the forced entry alarm. Thesystem does not have the ability to authenticate and identify the accessusing one or more keys. This situation is disadvantageous since theaccuracy of the access control system is compromised due to theunidentified entry.

It would therefore be desirable to provide a method and access controlsystem utilizing the method for identifying a key used in a door lock.It would further be desirable for the method and access control systemto determine if action is required based on the key identification. Itwould also be desirable for the method and access control system toidentify the key and electronically allow access to a secure area byremotely opening a door based on the key identification.

SUMMARY OF THE INVENTION

A system for controlling access to a secure area including a lock havinga locked and unlocked position for controlling access to a secure area.The lock includes pins for locking and unlocking the lock, and the pinsinclude a predetermined position for unlocking the lock. An electronicaccess device communicates with the pins for electrically measuringmovement of the pins and determining an unlock pin code for thepredetermined position of the pins for unlocking the lock. Theelectronic access device electrically measures pin movement by a key anddetermines a key code for the key from the pin movement. A controldevice electrically communicates with the electronic access device, andthe control device identifies the key code and determines when the keycode matches the unlock pin code.

In a related aspect, the control device controls access to the securearea using an access interface proximal to the lock. The control devicemay control access to the secure area using at least one governing pinin the lock. The control device allows access using the governing pinwhen the key code matches the unlock pin code and denies access usingthe governing pin when the key code does not match the unlock pin code.The pins may each include shear points aligning with a cylinder shearline for unlocking the lock when the key code matches the unlock pincode.

In a related aspect, the pins are a first set of pins and the systemfurther includes a second set of pins in the lock. Each pin of thesecond set of pins includes a shear point aligning with a cylinder shearline. An actuator in the lock communicates with the second set of pins,and the actuator is controlled by the control device for moving thesecond set of pins to align with the shear line for unlocking the lockwhen the key code matches the unlock pin code. In another embodiment,multiple pin codes allow respective multiple key codes from respectivekeys to allow access using the control device. The pin movement may bemeasured by a resistance measurement of a spring biasing the pin towardsa key insertion passageway in the lock. The pin movement may be measuredby a tension measurement of a spring biasing the pin towards a keyinsertion passageway in the lock. The pin movement may be measured usingcapacitance. The capacitance may be measured by sensing increasedcapacitance when the pin is pushed into a cylinder in the lock by thekey. In another embodiment, the pin movement may be measured usinginductance. The inductance my be measured by measuring the length of aspring biasing the pin towards a key insertion passageway in the lock.

In a related aspect, the control device determines a security event bydetermining when the key code matches the unlock pin code. The controldevice may also generate a signal when the key code does not match theunlock pin code.

In another aspect of the invention, a method for controlling access to asecure area comprises: controlling access to a secure area using a lockhaving a locked and unlocked position, the lock including pins forlocking and unlocking the lock, the pins including a predeterminedposition for unlocking the lock; electrically measuring movement of thepins using an electronic access device communicating with the pin;determining an unlock pin code for the predetermined position of thepins for unlocking the lock; measuring pin movement by a key using theelectronic access device; determining a key code for the key from thepin movement; identifying the key code using a control deviceelectrically communicating with the electronic access device; anddetermining when the key code matches the unlock pin code forauthenticating the key using the control device.

In another aspect of the invention, a computer program product comprisesa computer readable medium having recorded thereon a computer programfor enabling a processor in a computer system to control access to asecure area, the computer program performing the steps of controllingaccess to a secure area using a lock having a locked and unlockedposition, the lock including pins for locking and unlocking the lock,the pins including a predetermined position for unlocking the lock;electrically measuring movement of the pins using an electronic accessdevice communicating with the pin; determining an unlock pin code forthe predetermined position of the pins for unlocking the lock; measuringpin movement by a key using the electronic access device; determining akey code for the key from the pin movement; identifying the key codeusing a control device electrically communicating with the electronicaccess device; and determining when the key code matches the unlock pincode for authenticating the key using the control device.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects, features and advantages of the presentinvention will become apparent from the following detailed descriptionof illustrative embodiments thereof, which is to be read in connectionwith the accompanying drawings, in which:

FIG. 1 is a block diagram of a system for controlling access to a securearea according to an embodiment of the invention;

FIG. 2 is side elevational view of a door strike, door, access device,and access interface and a detail block diagram of a control device, ofthe system shown in FIG. 1;

FIG. 3 is a perspective view of a lock using a measuring device formeasuring resistance;

FIG. 4 is a detail perspective view of a pin, spring and cylinderhousing shown in FIG. 3;

FIG. 5 is a perspective view of another embodiment of a lock accordingto the invention using a measuring device for measuring tension;

FIG. 6 is a perspective view of another embodiment of a lock accordingto the invention using a measuring device for measuring capacitance andinductance;

FIG. 7 is a detail perspective view of the cylinder housing and ameasuring device shown in FIG. 6;

FIG. 8 is a perspective view of another embodiment of a lock accordingto the invention using an actuator and spring platform;

FIG. 9 a is a detail block diagram of the spring platform and theactuator shown in FIG. 8 having a retracted rod;

FIG. 9 b is a detailed block diagram of the spring platform and actuatorshown in FIG. 9 a having the rod extended; and

FIG. 10 is a perspective view of another embodiment of a lock accordingto the invention using magnets.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1-3, according to one embodiment of the presentinvention, a system 10 for controlling access to a secure area 15defined by walls 14 includes an entryway embodied as a door 18. The door18 includes a lock 20 having a locked and unlocked position forcontrolling access to the secure area 15 by locking against a doorstrike 16 which is a portion of the wall 14. The lock 20 includes pins24 (FIG. 3) for locking and unlocking the lock 20. The lock 20 furtherincludes predetermined pin positions for unlocking the lock 20. Anelectronic access device 22 communicates with the pins 24 forelectrically measuring movement of the pins, Movement of the pins 24 isdigitalized as a pin code determined for each pin. An unlock pin code ismeasured using predetermined pin positions for unlocking the lock 20.The electronic access device 22 also measures pin movement by a key 70.The key 70 includes teeth 72 which move the pins 24 in their respectivecylinder housings 36, and the electronic access device 22 determines akey code for the key 70 from the pin movement. The access device 22includes a microprocessor 23 for analyzing and determining measurementof the movement of the pins 24 and determining the pin code.

A control device 60 electrically communicates with the access device 22.The control device 60 includes a computer readable medium embodied as adata storage device 64 having a program 62 stored therein, and isconnected to a processor 68. Using the program 62, the control device 60identifies the key code received from the access device 22 and verifiesthe key code by determining whether the key code matches the unlock pincode for unlocking the lock to determine authentication of the key.Thereby, the control device 60 identifies and verifies or authenticatesthe key 70. The control device 60 also records entry into the securearea 15 using either card access or key entry. Further, the controldevice 60 identifies when the lock 20 is opened using an unidentifiedkey, for example, a false or blank key used to compromise the lock.Additionally, the control device 60 generates an alarm or a signal 69,for example, using a transceiver 65, to communicate a security event,e.g., an unauthorized entry. The signal may be sent to a receivingentity such as authorized personnel or a remote monitoring station 69 a.The security event is triggered when the key code does not match theunlock pin code for the predetermined position of the pins for unlockingthe lock, and thus the key 70 is not authenticated.

An access interface embodied as a reader 50 communicates with thecontrol device 60 and includes a microprocessor 54. A user providesidentification to gain entry into the secure area 15 by presenting, forexample, an access identification (ID) card (not shown) for swipingthrough the reader 50. The access device 50 includes the microprocessor(μP) 54 for reading the ID card and communicating with the controldevice 60. The access device 50 communicates with the control device 60which analyzes and identifies the ID card.

Referring to FIGS. 3 and 4, each of the pins 24 includes a shear point26. The lock 20 includes an internal rotatable cylinder 30 defining ashear line 32 between the lock 20 and the rotatable cylinder 30. Thelock 20 is opened by aligning the pin shear points 26 with the shearline 32 using the key 70 and rotating the cylinder 30. Springs 34 arepositioned in cylinder housings 36 and mate with the top of each pin 24for providing mechanical resistance to the pin moving upward in thecylinder housing 36.

In one embodiment of the invention, referring to FIGS. 3 and 4,resistance is measured on each pin 24 using a measuring device 40. Theresistance increases as the pin 24 is pushed up upwards in the cylinderhousing 36. The microprocessor 23 of the access device 22 processes themeasurement of the pin 24 movement using the resistance measurement, anddetermines the key code from the pin movement. The key code iscommunicated 41 to the control device 60 for identifying and verifyingthe key and recording the entry into the secure area 15. Thus, theaccess control system 10 maintains accountability for any card holder orkey holder entering through the door.

Referring to FIG. 5, in another embodiment of the invention, a measuringdevice 44 measures spring 34 tension on each pin 24. The measuringdevice 44 is inserted between the spring 34 and the cylinder housing 36.The tension reading increases as the pin 24 is pushed upwards in thecylinder housing 36. The tension reading is processed by themicroprocessor 23 of the access device 22 to determine the measurementof the pin 24 movement and determine the key code from the pin 24movement. As in the embodiment shown in FIGS. 3 and 4, the key code iscommunicated to the control device 60 for identifying the key andrecording the entry into the secure area 15.

Referring to FIGS. 6 and 7, in another embodiment of the invention,capacitance is measured on each pin 24 using a measuring device 46. Thecapacitance increases as the pins 24 are pushed upwards into thecylinder housing 36. The capacitance reading is processed by themicroprocessor 23 of the access device 22 to determine the measurementof the pin 24 movement and determine the key code from the pin movement.

In another embodiment, the measuring device 46 measures inductance foreach pin 24. The inductance of each spring 34 is measured using themeasuring device 46, which will be inversely proportional to the lengthof the spring 34. Thus, as the pin 24 is pushed upwards in the cylinderhousing 36, the inductance increases. Similarly, the inductance readingis processed by the microprocessor 23 of the access device 22 todetermine the measurement of the pin 24 movement and determine the keycode from the pin movement.

Referring to FIGS. 8, 9 a and 9 b, another embodiment of the inventionincludes a lock 82 including a cylinder 86 having an upper part 82 a anda lower part 82 b, where like elements to the lock 20 shown in FIGS. 1-6have the same reference numerals. The lock 80 includes pins 24 withshear points 26 (or shear pins 24) in the upper part 82 a of thecylinder 86, and solid pins 90 in the lower part 82 b of the cylinder86. The solid pins 90 are positioned in cylinder housings 92 whichrotate with the cylinder 86 with a master key 100 which opens the lock80. The master key 100 is double sided, i.e., has teeth 102 opposite oneanother. The solid pins 90 do not have a shear point as the pins 24 inthe upper part 82 a of the cylinder 86. The solid pins 90 movements inthe cylinder housings 92 and measured to identify the master key 100. Ifthe master key 100 key code or identification generated by the solidpins 90 matches an unlock pin code or authorized identification numbers,then the control device 60 unlocks the lock by moving the shear points26 of the pins 24 in alignment with the shear line 88. In thisembodiment, the pins 24 act as governing pins controlled by the controldevice 60. When the shear points 26 of the pins 24 and the shear line 88are aligned, the cylinder 86 will turn and unlock the lock 80. Thus, akey code is generated from the master key 100 which is identified,recorded and verified by the control device 60.

Additionally, referring to FIGS. 9 a and 9 b, the shear pins 24 aremounted to a spring board 98 which is controlled by a solenoid oractuator 94 connected to the control device 60 for controlling the shearpins 24. The actuator 94 uses an extendable rod 96 to push the springboard 98 in the downward direction as shown in FIG. 9 a, pushing theshear points 26 of the pins 24 below the shear line 88 and locking thelock 80. When the actuator 94 retracts the rod 96, the spring board 98moves upward aligning the shear points 26 of the pins 24 with the shearline 88 of the lock 80 for unlocking the lock 80, as shown in FIG. 9 b.

Referring to FIG. 10, another embodiment of the invention using a lock110, including magnets 112 instead of springs 34, wherein like elementswith the lock 80 shown in FIG. 8 have the same reference numerals. Eachpin 24 is magnetically charged having a positively charged side 114 anda negatively charged side 116. The surrounding cylinder housing 36 ismade of non-magnetic material. The pins 24 are pushed down when themagnets 112 are charged positively. In this state, the shear points 26of the pins are below the shear line 88 and the lock 110 is locked. Whenthe magnets 112 are charged negatively, the pins 24 are pulled upward sothe shear points 26 align with the shear line 88 to unlock the lock 110.

Thereby, the present invention solves the problem of identifying a keyin a lock, particularly in a duel access security system havingelectronic access and a lock, by measuring how the key presses or movesthe pins in the lock. The movement is analyzed to determine anidentification number associated with the measurement or key code, whichis sent to the control device 60. The control device 60 records theevent and may control additional pins, such as the solid pins 90 inFIGS. 8 and 10 in the lock 80, or lock 110. When the key code isacceptable or verified, the lock opens mechanically using the locksshear line 86. Using electrically controlled pins 24 as governing pins,the lock 80 or lock 110 for the door 18 may be programmed to accept keyshaving different identification numbers, and will not be limited to thekey pattern that lines up pins along a shear point, because the controldevice 60 lines up the shear points 26 with the shear line 88.

Thereby, the embodiment of the present invention provide completeaccountability of all entries into a secure area 15 through the door 18.Additionally, the lock is able to use more than one key to unlock thelock as the mechanical opening is controlled by the control device 60 inthe embodiments shown in FIGS. 8 and 10. The key codes may be changed atthe control device 60 which is a significant improvement in timeefficiency and cost than changing the pins in a lock. The system andmethod of the present invention is also advantageous where amultiplicity of electronic access and mechanical locks coexists in aseries, for example, on the same floor of a building, for example, as inU.S. patent application Ser. No. (11/782,557), incorporated byreferenced hereinbefore.

While the present invention has been particularly shown and describedwith respect to preferred embodiments thereof, it will be understood bythose skilled in the art that changes in forms and details may be madewithout departing from the spirit and scope of the present application.It is therefore intended that the present invention not be limited tothe exact forms and details described and illustrated herein, but fallswithin the scope of the appended claims.

1. A system for controlling access to a secure area, comprising: a lockhaving a locked and unlocked position for controlling access to a securearea, the lock including pins for locking and unlocking the lock, thepins including a predetermined position for unlocking the lock; anelectronic access device communicating with the pins for electricallymeasuring movement of the pins and determining an unlock pin code forthe predetermined position of the pins for unlocking the lock, theelectronic access device electrically measuring pin movement by a keyand determining a key code for the key from the pin movement; and acontrol device electrically communicating with the electronic accessdevice, the control device identifying the key code and determining whenthe key code matches the unlock pin code to authenticate the key.
 2. Thesystem of claim 1, wherein the control device controls access to thesecure area using an access interface proximal to the lock.
 3. Thesystem of claim 1, wherein the control device controls access to thesecure area using at least one governing pin in the lock, the controldevice allowing access using the governing pin when the key code matchesthe unlock pin code and denying access using the governing pin when thekey code does not match the unlock pin code.
 4. The system of claim 3,wherein the pins each include shear points aligning with a cylindershear line for unlocking the lock when the key code matches the unlockpin code.
 5. The system of claim 3, wherein the pins are a first set ofpins and the system further including: a second set of pins in the lock,each pin of the second set of pins includes a shear point aligning witha cylinder shear line; an actuator in the lock communicating with thesecond set of pins, the actuator being controlled by the control devicefor moving the second set of pins to align with the shear line forunlocking the lock when the key code matches the unlock pin code.
 6. Thesystem of claim 3, wherein multiple pin codes allow respective multiplekey codes from respective keys to allow access using the control device.7. The system of claim 1, wherein the pin movement is measured by aresistance measurement of a spring biasing the pin towards a keyinsertion passageway in the lock.
 8. The system of claim 1, wherein thepin movement is measured by a tension measurement of a spring biasingthe pin towards a key insertion passageway in the lock.
 9. The system ofclaim 1, wherein the pin movement is measured using capacitance.
 10. Thesystem of claim 9, wherein the capacitance is measured by sensingincreased capacitance when the pin is pushed into a cylinder in the lockby the key.
 11. The system of claim 1, wherein the pin movement ismeasured using inductance.
 12. The system of claim 11, wherein theinductance is measured by measuring the length of a spring biasing thepin towards a key insertion passageway in the lock.
 13. The system ofclaim 1, wherein the control device determines a security event bydetermining when the key code matches the pin code.
 14. The system ofclaim 13, wherein the control device generates a signal when the keycode does not match the pin code.
 15. A method for controlling access toa secure area, comprising: controlling access to a secure area using alock having a locked and unlocked position, the lock including pins forlocking and unlocking the lock, the pins including a predeterminedposition for unlocking the lock; electrically measuring movement of thepins using an electronic access device communicating with the pin;determining an unlock pin code for the predetermined position of thepins for unlocking the lock; measuring pin movement by a key using theelectronic access device; determining a key code for the key from thepin movement; identifying the key code using a control deviceelectrically communicating with the electronic access device; anddetermining when the key code matches the unlock pin code forauthenticating the key using the control device.
 16. A computer programproduct comprising a computer readable medium having recorded thereon acomputer program for enabling a processor in a computer system tocontrol access to a secure area, the computer program performing thesteps of: controlling access to a secure area using a lock having alocked and unlocked position, the lock including pins for locking andunlocking the lock, the pins including a predetermined position forunlocking the lock; electrically measuring movement of the pins using anelectronic access device communicating with the pin; determining anunlock pin code for the predetermined position of the pins for unlockingthe lock; measuring pin movement by a key using the electronic accessdevice; determining a key code for the key from the pin movement;identifying the key code using a control device electricallycommunicating with the electronic access device; and determining whenthe key code matches the unlock pin code for authenticating the keyusing the control device.